Question

two electrons are an angstrom (1x10^-10m) apart. What electrostatic force do they exert on one another?

Answer 1

2.30 × 10⁻⁸ N if the two electrons are in a vacuum.

Step-by-step explanation:

The Coulomb's Law gives the size of the electrostatic force
`F` between two charged objects:

`\displaystyle F = -(k\cdot q_1 \cdot q_2)/(r^(2))`,

where

• 
  `k` is coulomb's constant.
  `k = 8.99* 10^(8)\;\text{N}\cdot\text{m}^(2)\cdot\text{C}^(-2)` in vacuum.
• 
  `q_1` and
  `q_2` are the signed charge of the objects.
• 
  `r` is the distance between the two objects.

For the two electrons:

• 
  `q_1 = q_2 = 1.60* 10^(-19)\;\text{C}`.
• 
  `r = 1* 10^(-10)\;\text{m}`.

• 
  `\displaystyle F = -(k\cdot q_1 \cdot q_2)/(r^(2)) = -(8.99* 10^(8)* (1.60* 10^(-19))^(2))/((1* 10^(-10))^(2)) = 2.30* 10^(-8)\;\text{N}`.

The sign of
`F` is negative. In other words, the two electrons repel each other since the signs of their charges are the same.